The Beast (1988)

In 1981 Afghanistan, a Soviet tank unit viciously attacks a Pashtun village harboring a group of mujahideen fighters. Following the assault, one of the tanks—commanded by ruthless commander Daskal (George Dzundza)—takes a wrong turn through a mountain pass and enters a blind valley. Taj (Steven Bauer) returns to discover the village destroyed, and his father and brother killed—the latter by having been crushed under Daskal's tank. As the new khan following his brother's death, Taj is spurred to seek revenge and leads a band of mujahideen fighters into the valley to pursue Daskal's tank (which they call 'The Beast'), counting on their captured RPG-7 anti-tank weapon to destroy it. Lost, isolated, and with their radio damaged in the village attack, the tank crew set out to find Kandahar Road and return to Soviet lines. While camping for the night, Afghan communist crewman Samad (Erick Avari) educates the reluctant tank driver, Konstantin Koverchenko (Jason Patric), about the Pashtun people's code of honour, Pashtunwali; particularly nanawatai, which requires that an enemy is to be given sanctuary if he asks. Wiki